Simulation, Sizing and Analysis of High Pressure Hydrogen All Electrochemical Decentralized Refueling Station

The University of Applied Sciences Esslingen (UASE) is a partner in the collaborative EU project PHAEDRUS (high Pressure Hydrogen All Electrochemical Decentralized RefUeling Station) as part of the EU work programme SP1-JTI-FCH.2011.1.8 Research and Development of 700 bar refueling concepts and technologies. The subtask of UASE is the simulation, sizing and analysis of a new concept for a 100 MPa hydrogen refueling station enabling self-sustained infrastructure roll-out for early vehicle deployment volumes, showing the applicability of the electrochemical hydrogen compression (EHC) technology in combination with an on-site anion exchange membrane electrolyser (AEMEC), storage units, precooling and a dispensing system. The electrolyser and the compressor are modeled using the electrochemical equations and the conservation of mole balance. The main water flows, electro-osmotic drag and diffusion are added in the electrolyser model and the effect of hydrogen back diffusion is included in the compressor model. The storage is modeled thermodynamically using the energy balance equation. The components’ dynamic models are implemented and simulated in MATLAB/Simulink enabling the assessment of the different configurations, sizing components, calculation of efficiencies, capital (CAPEX) and operational (OPEX) expenditures. A sensitivity analysis is performed by varying the prices of the storage tanks and electricity. A hydrogen refueling station is analyzed by calculating the total cost, annuity, unit cost of hydrogen and payback period. This software tool allows the use of an optimization method in order to optimize the sizes of the different components especially that they are interdependent and in several cases inversely proportional.